Various techniques for assisting the driver of a vehicle have been developed. For example, Patent Literature 1 discloses a driving assistance device which specifies the stop position of the vehicle in advance on the basis of map information or traffic information, specifies a coasting start position for coasting to the stop position on the basis of the specified stop position and the coasting distance, and notifies the driver of, for example, the coasting start position (the accelerator is turned off) or the braking start position (the brake is turned on), thereby making the driver to drive the vehicle with low energy consumption.